Color

#21abc0

#21abc0
hex#21abc0
rgbrgb(33, 171, 192)
hslhsl(188, 71%, 44%)
oklchoklch(0.682 0.112 211)
Closest name: Aquarius (#2db0ce)Relative luminance 0.3325

Colors that go with #21abc0

Charcoal, Tomato and Amber lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.

Real palettes that use #21abc0

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#c03621

#21c085 · #215bc0

#c021ab · #abc021

Split-complementary

Open in tool →

#c0215b · #c08521

#8521c0 · #c03621 · #5bc021

Contrast

#21abc0 as textRatioAAAA largeAAAFix
Aaon white
2.74:1failfailfail
  • AA: use #188090 as the text (4.64:1)
  • AAA: use #12616d as the text (7.1:1)
  • AA: or shift the background to #333333 (4.6:1)
  • AAA: or shift the background to #0d0d0d (7.08:1)
Aaon black
7.65:1passpasspassPasses AAA — no fix needed.

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21abc0 as the background.

Brands using this color

Fonts for this mood

#21abc0 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #21abc0
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #21abc0 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21abc0-a2b7be-df4e81-1f252d-e9f1ee?lock=0&style=vibrant

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Machine-readable: color.md